Unbalance switch for centrifugal extractors



Oct. 25, 1960 J. c. MELLINGER UNBALANCE SWITCH Foa CENTRIFUGALExTRAcToRs Filed Sept. 4, 1959 2 Sheets-Sheet 1 dnvznlor John c Oct. 25,196() J. c. MELLINGER UNBALANCE SWITCH FOR CENTRIFUGAL EXTRACTORS 2Sheets-Sheet 2 Filed Sept. 4, 1959 IVI/Er e111' n et gen? UNBALANCESWITCH FOR CENTRIFUGAL EXTRACTORS John C. Mellinger, Newton, Iowa,assignor to The Maytag Company, Newton, Iowa, a corporation of DelawareFiled Sept. 4, 1959, Ser. No. 838,113

16 Claims. (Cl. ZOU-61.76)

This invention relates to a control mechanism for stopping andrestarting electrically controlled devices, and, more particularly, to`an unbalance switch for centrifugal extractors.

Many different types of unbalance switches have been designed forcentrifugal extractors, such `as in washing machines operable throughwash and spin-dry cycles. During the spin-dry operations, if an extremeunbalance condition occurs due to the uneven distribution of clothes,the tub may gyrate violently. Unbalance switches are designed generallyto open the circuit controlling the appliance, so that the machine isde-energized. The operator can then redistribute the clothes and restartthe operation.

It is an object of the present invention to provide an unbalance switchthat will de-energize an electrically controlled device duringpredetermined conditions. lt is a further object of the invention tomaintain an electrically controlled device in`de-energized conditionafter shut off due to unbalance conditions until restarted by theoperator. 1t is a still further object of the invention to provide lacontrol mechanism that is automatically reset upon opening of the lidafter the machine has been de-energized. It is another object of theinvention to provide a switch control that serves to function both as adoor interlock and as an unbalance switch which can be reset upon theopening of the door, as when the operator redistributes the clothes toremedy the conditions which cause the unbalance. It is still anotherobject of the invention to provide an unbalance control mechanism thatis positive and reliable in operation. It is yet another object of theinvention to provide a control device that is inexpensive in manufacturebecause of its simple arrangement. Further objects and advantages ofthis invention will become evident as the .description proceeds and froman examination of the accompanying drawings which illustrate oneembodiment of the invention and in which simi-lar numerals refer tosimil-ar parts throughout the several views.

In the drawings:

Figure 1 is a fragmentary top plan view of a washing machine, in whichthe top wall or" the cabinet is-` broken away to show the controlmechanism of the invention;

Figure 2 is an enlarged fragmentary view taken substantially along lines2-2 of Figure l;

Figure 3 is a view similar to Figure 2 illustrating the action of thecontrol mechanism during conditions of unbalance; and

Figure 4 is a sectional view taken substantially along lines 4-4 ofFigure 2.

Referring now to the drawings, there is shown a centrifugal extractor1t), such as employed in an upright clothes washing machine, whichincludes a tub 11 within which is journalled a clothes basket 12. Theentire washing machine is supported on a frame and enclosed in a cabinet14.

The access opening to the clothes basket 12 may be closed by a lid 15.The lid is pivoted about 16, the latl' 2,957,959 Patented Oct. 25, 1960ter of which is spaced a short distance from one end 17 of the lid, sothat the end 17 functions as a lever to engage the plunger end 21 andmove the plunger 20 to operate the control mechanism.

The plunger, or follower, 20 is slidably mounted in a bracket 22.Bracket 22 is substantially channel shaped in cross section having adepending front ange 23 which is secured by screws 24 to the cabinet 14of the appliance. The rear flange 25 is fastened to a cabinetcrossmember 18 by screws 26.

Plunger 20 projects through an opening 27 in the rear ange 25. Theplunger end 21, which engages lid 15, protrudes through the opening 28of front flange 23 and opening 29 of cabinet 14.

A base member 3i) is pivotally mounted in a recess formed in the bracket22, so that it may be moved between two positions, illustratedrespectively in Figures 2 and 3. Spring 33 is connected between anupright post 34 on the base member and a leg member 35 on the bracket 22to maintain the base member normally in the position illustrated inFigure 2.

A switch 38 is supported on a platform 37 of the base member. Switch 38has a spring biased button 40 for opening and closing electrical switchcontacts. When the base member is maintained in its normal position bythe spring 33, button 40 is aligned with, and adjacent to, the plunger20, so that it may be engaged thereby when the plunger is movedrearwardly by the closing action of the lid 15. The wire leads 41 of theswitch 38 may bo connected in series with the circuit for energizing thewashing in order that the machine may be tie-energized, or energized byswitch 38. When button 40 is depressed by the plunger 20 as the lid 15is closed, plunger 20 is moved rearwardly, and switch contacts in switch38 are closed to permit the machine to be operated. On the other hand,when the lid 15 is opened as shown in the dotted line position in Figure2, button 40 is permitted to move outwardly to open the switch contactsof switch 38 to de-energize the electrical circuit.

Depending arm 42 connected to the base member 30 is located in `aposition to be cont-acted by bumper 43 affixed to the tub 11, when thetub is gyrating excessively, `due to unbalance conditions wihtin thebasket 12. Thus, if the tub 11 nutates violently because of the unevendistribution of clothes in the basket 12, bumper 43 contacts arm 42 ofthe base member 3l), as shown in Figure 3, to pivot the base member to atiited position against the tension of spring 33. It will be noted thatin tilted position, switch 38 is moved rearwardly away from plunger 20,to release button 40 'and open the switch contacts of switch 38, andthus, de-energize the machine.

A latch 45 maintains the base member 3l) in the tilted position ofFigure 3 until released. In the particular form shown in the drawings,the latch includes a sleeve 46 slidably mounted on plunger 20, adepending leg 44, and a keeper 47. The keeper is in the form of ashoulder 47 above the base member 30 adapted to project through opening48 in the arm member 42, and engage the lower surface of the base member30 when the latter is lifted by the bumper 43 during conditions ofunbalance, as shown in -Figure 3. Spring 49 between flange 23 and sleeve46 biases the latch toward the base member 30, so that the keeperimmediately snaps through the opening 48 as the arm 42 is lifted. Thekeeper ordinarily is prevented from entering the opening 48, exceptduring a condition of unbalance, by a stop, or ledge 50 at the end ofkeeper 47 which abuts the end of the base member 30.

A stop 52 in the form of a finger projects through the opening 48 tosupport the base member 30. Spring in a counter-clockwise direction.However, the base member in the normal position is supported on the stop52, the latter of which, however, permits clockwise rotation of the basemember to the tilted position illustrated in Figure 3.

A return spring 54 is mounted between the flange 25 of bracket 22 and apin 56 aiiixed to the plunger 20. Compression of spring 54 biases theplunger in theV direction of the lid 15, so that, when the latter israised, the plunger end 21 is projected through the opening 29 in thecabinet 14. Washer 57 may be interposed between the spring and pin 56.

A stop in the form of a boss 58 on plunger 20 on the opposite side offlange 25 prevents the plunger from being ejected through the opening 27of the cabinet when the lid is lifted.

It will be noted that when the plunger is moved by the lid to depressswitch button 4t?, pin 56 is separated from sleeve "46 of the latch.This spacing permits freedom of movement of the latch to engage the basemember in tilted position, as discussed above. However, when the keeperis engaged, as in Figure 3, sleeve 46 is adjacent pin 56, and adapted tobe contacted thereby when the lid is raised.

Return spring 54 is stronger than the latch spring 49, so that thelatter is overcome by the former when the lid is opened. Since spring 54is more powerful than spring 49, the latch `45 is moved from right toleft as shown in the drawings by pin 56 pushing sleeve 46 against spring49. Thus, assuming keeper 47 has been inserted through opening `48 tomaintain the base member 30 in a tilted position as shown in Figure 3,upon opening the lid 15, return spring 54, by virtue of its greaterstrength, forces the sleeve 46 against spring 49 from right to left,thereby withdrawing the keeper from the opening y48 of arm 42, whileplunger is moved, at the same time, to project end 21 through theopening 29 of the cabinet.

From the foregoing description, it is believed that the operation of thecontrol mechanism of the invention is apparent. When the operator raiseslid of the washer, for instance, to insert clothes, as shown by thedotted lines in Figure 2, the plunger 2t) is moved from right to left bythe return spring 54 to release the switch button 40, open the switchcontacts of switch 38, and de-energize the machine. However, when thelid 15 is closed, the lever end 17 of the door engages plunger end 21 tomove the plunger from left to right, depress the switch button 40 andclose the switch contacts of switch 38, and energize the electricallycontrolled appliance. If a condition of unbalance should occur duringoperation in which the tub 11 gyrates eX- cessively, then bumper K43engages the arm 42, base member 30 and platform 37 are tiltedrearwardly, and the switch 38 rotated in a direction away from theplunger 20. This permits the switch button 40 to be released opening thecontacts of the switch 38 to stop the machine. At the same time, latchspring 49 biases the keeper 47 through opening `48 to maintain the basemember in the tilted position, shown in Figure 3. Switch 38 remains inthis position with the base member supported by latch 45 and the machinekept de-energized until the control mechanism is reset.

The control is reset by opening the lid 15. This releases the end 21 ofthe plunger 20, so that the return spring 54 moves the latch 45, as wellas plunger 20, from right to left and keeper is withdrawn from theopening 48 by pin 56 engaging sleeve 46. The platform is returned to thenormal position by spring 33, as shown in Figure 2, with the base memberresting yon finger 52.

The control having been rmet by opening the lid 15, the machine is againenergized by closing the lid, as previously described.

In practice, if the operator observes that the machine has been stoppedduring the centrifugal extraction operation, it is only necessary tolift the lid 15 and close it again to restart the machine. This is aconvenient operation, since the procedure is ordinarily followed inorder to manually redistribute the clothes within the basket toeliminate the conditions causing unbalance.

In the drawings and specification there has been set forth a preferredembodiment of the invention, and although speciiic terms are employed,these are used in a generic and descriptive sense only, and not forpurposes of limitation. Changes in form and the proportion of parts, aswell as the substitution of equivalents are contemplated, ascircumstances may suggest or render expedient, without departing fromthe spirit or scope of this invention as further defined in thefollowing claims.

l claim:

l. The combination comprising, a base member pivotably mounted formovements between first and second positions, switch means mounted onsaid base member, means biasing said base member to the iirst position,follower means movably mounted for engaging and holding said switchmeans in closed position when said base member is in the iirst position,and an arm member on said base member for pivoting said base member tothe second position under predetermined conditions for disengaging saidswitch means from said follower means.

2. The combination comprising, a base member pivotably mounted formovements between iirst and second positions, switch means mounted onsaid base member, means for normally maintaining said base member in theiirst position, follower means movably mounted for engaging and holdingsaid switch means in closed position when said base member is in theiirst position, an arm member on said base member for pivoting said basemember to the second position under predetermined conditions fordisengaging said switch means from said follower means, and means forkeeping said base member in the second position after occurrence of thepredetermined condition until released.

3. The combination comprising, a base member pivotably mounted formovements between rst and second positions, switch means mounted on saidbase member, means biasing said base member to the irst position,follower means movably mounted for engaging and holding said switchmeans in closed position when said base member is in the lirst position,an arm member on said base member for pivoting said base member to thesecond poistion under predetermined conditions for disengaging saidswitch means from said follower means, and latch means for keeping saidbase member in the second position after such occurrence ofpredetermined conditions until released.

4. The combination comprising, -a base member pivotably mounted formovements between first and second positions, switchrneans mounted onsaid base member, spring means biasing said base member to the firstposition, follower means movably mounted on said support member forengaging :and holding said switch means in closed position when saidbase member is in the rst position, an arm member on said base memberfor pivot- -ing said base member to a second position underpredetermined conditions for disengaging said switch means from saidfollower means, and releasable latch means for keeping said base memberin the second position against the bias of said spring means after suchoccurrence of predetermined conditions until released.

`5. The combination comprising, a base member pivotably mounted formovements between first :and second positions, switch means mounted onsaid base member, means biasing said base member to the first position,follower means movably mounted for engaging and holding said switchmeans in closed position when said base member is in the iirst position,an arm member on said base member for pivoting said base member to thesecond position under predetermined conditions to disengage said switchmeans from said follower means, and spring biased latch means forkeeping said base member in the second position after such occurrence ofpredetermined conditions until released, and means associated with saidfollower means for releasing said spring biased latch means.

6. A device of the character described comprising, a pivotally mountedbase member, switch means secured to said base member, follower meansmovably mounted for engaging and holding said switch means in closedposition, an arm member on said base member adapted to be moved underpredetermined conditions for pivoting said base member in one directionfor disengaging said switch means from said follower means, meansbiasing said base member in the opposite direction, and latch meansassociated with said arm member for keeping said base member in pivotedposition in which said switch means is disengaged from said followermeans until released.

7. In combination: a support member, a pivotally mounted base member,switch means secured to said base member, follower means movably mountedfor engaging and holding said switch means in closed position, an armmember on said base member for pivoting said base member in onedirection under predetermined conditions to disengage said switch meansfrom said follower means, means biasing said base member in the oppositedirection, latch means associated with said arm member for keeping saidbase member in pivoted position in which said switch means is disengagedfrom said follower means, and means for releasing said latch means.

8. In an electrically controlled centrifugal extractor, a frame, a lidmember for the extractor mounted on said frame for opening and closingmovements, a base member pivotably mounted for movements between firstand second positions, means biasing said base member to the firstposition, switch means for controlling the extractor mounted on saidbase member, follower means movably mounted between said lid member andswitch means for engaging and holding said switch means in closedposition when said lid member is closed and when said base member is inthe first position, an arm member on said base member adapted to beengaged by the centrifugal extractor during conditions of unbalance topivot said base member to the second position for disengaging saidswitch means from said follower means, and releasable means for keepingsaid base member in the second position.

9. In an electrically controlled centrifugal extractor, a frame, a lidmember for the extractor mounted on said frame for opening and closingmovements, a base member pivotably mounted for movements between rst andsecond positions, spring means for biasing said base member to the firstposition, switch means for controlling the extractor mounted on saidbase member, follower means movably mounted on said support memberbetween said lid member and switch means for engaging and holding saidswitch means in closed position when said lid member is closed and whensaid base member is in the first position, `an arm member on said basemember adapted to be engaged by the centrifugal extractor duringconditions o-f unbalance rto pivot said base member to the secondposition for disengaging said switch means from said follower means,latch means for keeping said base member against the bias of said springmeans in the second position until released, and means for releasingsaid latch means when said lid member is opened.

l0. In an electrically controlled centrifugal extractor, a frame, a lidmember for the extractor mounted on said frame for opening and closingmovements, a base member pivotably mounted for movements between firstand second positions, means biasing said base member to the rstposition, switch means for controlling the extractor mounted on saidbase member, follower means movably mounted on said support memberbetween said lid member and switch means for engaging and holding saidswitch means in closed position when said lid member is closed and whensaid base member is in Ithe rst 6 position, an arm member on said basemember adapted to be engaged by the centrifugal extractor Vduringconditions of unbalance for pivoting said base member to the secondposition to disengage said switch means from said follower means, latchmeans for keeping said base member in the second position untilreleased, Iand means operatively associated with said -follower meansfor releasing said latch means when said lid member is opened.

ll. In an electrically controlled centrifugal extractor, a frame, a lidmember mounted on said frame for opening `and closing movements, a basemember pivotally mounted for movements between rst and second positions,switch means for controlling said extractor mounted on said base member,a plunger movably mounted between said lid member and switch means forengaging and holding said switch means in closed position when said lidmember is closed, means biasing said base member to the first positionin which said switch means is operatively engaged by said plunger, meansfor pivoting said base member to the second position away from saidplunger to disengage said switch means under predetermined conditions,latch means for keeping sa-id base member in the second position untilreleased, a trip member on said plunger for releasing said latter means,and spring means biasing said trip member to release said latch memberwhen said lid member is opened.

l2. In an electrically controlled centrifugal extractor, a frame, a lidmember mounted on said frame for opening and closing movements, a basemember pivotally mounted for movements between rst and second positions,switch means for controlling said extractor mounted on said base member,`a plunger movably mounted between said lid member and switch means forengaging and holding said switch means in closed position when said lidmember is closed, means biasing said base member to the first positionin which said switch means is operatively engaged by said plunger, meansfor pivoting said base member to the second position Iaway from saidplunger -to disengage said switch means under predetermined conditions,spring biased latch means for keeping said base member in the secondposition until released, and la member on said plunger for releasingsaid latter means when said lid member is opened.

13. In an electrically controlled centrifugal extractor, a frame, a lidmember mounted on said frame for opening and closing movements, a basemember pivotally mounted for movements between iirst and secondpositions, switch means for controlling said extractor mounted on saidbase member, -a plunger operatively associated with said lid membermovably mounted for engaging and holding said switch means in closedposition when said lid member is closed, means biasing said base memberto the rst position in which said switch means is operatively engaged bysaid plunger, means for pivoting said base member lto the secondposition away from said plunger to disengage said switch means underpredetermined conditions, latch means for keeping said base member inthe second position until released, and means operatively associatedwith said plunger for releasing said latter means when the lid member isopened.

14. In an electrically controlled centrifugal extractor, a frame, a lidmember mounted on said frame for opening and closing movements, a basemember pivotally mounted for movements between first and secondpositions, switch means for controlling said extractor mounted on saidbase member, a plunger movably mounted between said lid member andswitch means for engaging and holding said switch means in closedposition when said lid member is closed, means biasing said base memberto the rst position in which said switch means is operatively engaged bysaid plunger, means for pivoting said base member to the second positionaway from said plunger to disengage said switch means underpredetermined conditions, means for keeping said base member in thesecond position until released, and means for releasing said lattermeans when the lid member is opened. 15. In an electrically controlledcentrifugal extractor, a frame, a lid member mounted on said frame -oropening and closing movements, a base member pivotally mounted formovements between tirst and second positions, switch means forcontrolling said extractor mounted on said base member, `a plungermovably mounted between said -lid member and switch means for engagingand holding said switch means in closed position when said ylid memberis closed, means biasing said base member to the iirst position in whichsaid switch means is operatively engaged by said plunger, means forpivoting said base member to the second position away from said plungerto disengage said switch means under predetermined conditions, andreleasable means for keeping said base member in the second position.

16. In an electrically controlled centrifugal extractor, a trarne, a lidmember mounted on said frame for opening and closing movements, a .basemember pivotally mounted for movements between rst and second positions,switch means for controlling said extractor mounted on said base member,a plunger movably mounted between said -lid member and switch means forengaging and holding said switch means in closed position when said lidmember is closed, means biasing said base member to the rst position inwhich said switch means is operatively engaged by said plunger, meansfor pivoting said base member to the second position away from saidplunger to disengage said switch means under predetermined conditions,and releasable spring biased latch means for keeping said base member inthe second position.

References Cited in the le of this patent UNITED STATES PATENTS1,394,398 Benjamin Oct. 18, 1921 2,882,360 VSisson Apr. 14, 19592,921,155 Basso Ian. 12, 1960

